1. Field of the Invention
The present invention relates to a solid state imaging apparatus and an imaging system.
2. Description of the Related Art
Aimed at high-speed reading of pixel signals of pixels arranged in each column in a complementary metal oxide semiconductor (CMOS) image sensor designed so that a single pixel amplifier is shared by a plurality of photoelectric conversion elements, in Japanese Patent Application Laid-Open No. 2011-130032, there is disclosed a technology of simultaneously reading pixel signals in two rows with use of two vertical output lines arranged for each column of pixels.
In Japanese Patent Application Laid-Open No. 2011-130032, the following configuration is disclosed as one embodiment of an imaging element. A pixel set includes two photodiodes and two transfer switches. The pixel set further includes a single reset switch, a single pixel amplifier, and a single row selecting switch. The two photodiodes are connected to a single floating diffusion portion via the respective transfer switches, and share the reset switch, the pixel amplifier, and the row selecting switch.
In the above-mentioned configuration, two vertical output lines are arranged for each column of pixels. With this, pixel signals of two pixel sets that are consecutive in the direction along the column can be simultaneously read from the two vertical output lines. In this way, the area of the photodiodes can be secured and high-speed reading can also be attained. Note that, in the embodiment, the pixel signals are simultaneously read from two rows selected as respective rows of two consecutive pixel sets, rather than from two rows within the same pixel set.
In the configuration as described above in which the pixel signals are simultaneously read from two vertical output lines, the order of the reading may fail to match with the actual spatial arrangement of pixels. In the above-mentioned technology, the pixel signals are not read as indicated by spatial information. In addition, also in another configuration in which a single photoelectric conversion element is arranged for a single pixel amplifier, the pixel signals may fail to be read as indicated by spatial information. It is accordingly necessary to sort the pixel signals as indicated by the spatial information with use of an external digital signal processing circuit.